Talk overview 2 nd Annual Physical Activity Summit Dr Alan Barker Children s Health and Exercise Research Centre (CHERC) A.R.Barker@exeter.ac.uk @CHERC_UoE Paediatric origins of cardiovascular disease (CVD) Importance of vigorous intensity physical activity (PA) for improving health in youth High-intensity interval exercise (HIIE) as a model to promote health Key messages Other work in CHERC (if time) Non-communicable diseases deaths = 36 million people/year CVD = 17.5 million Cancer = 8.2 million Respiratory diseases = 4 million Diabetes = 1.5 million Big four explain 82% of NCD deaths Smoking, physical inactivity, diet and alcohol CVD and mortality CVD: UK data in 2014 ~41,000 premature deaths in UK/year British Heart Foundation. CVD Statistics (2014) Atherosclerosis and age What are CVD risk factors? Age Sex Family history Insulin Resistance HDL : LDL Atherosclerosis starts in childhood Blood Pressure CVD Risk Dyslipidaemia Obesity Total Cholesterol Physical inactivity Low Fitness Smoking Exposure to CVD risk factors promotes a covert, preclinical progression of the disease 1
Atherosclerosis has its origins in childhood: The Bogalusa Heart Study Tracking of CVD risk Autopsy studies on 204 young persons No. risk factors Child health Arterial health is directly related to CVD risk factor status? Adult health Teenagers with clustered CVD risk are 6 times more likely to present with clustered CVD risk factors in adulthood Berenson et al. (1998). New Eng J Med. 338:1650-1656 Andersen et al. (2004). Int J Behav Nutr Phys Act. 1: 6 Reducing risk is a priority: Life s Simple 7 steps What proportion of children have ideal CV health? 856 participants aged 12 to 18 y at baseline with 21 years follow-up BMI Physical activity Diet score Smoking status Cholesterol Blood pressure Glucose Ideal child CV health index 1 2 3 4 5 6 Number 15 102 312 294 115 18 Percent 1.8% 11.9% 36.4% 34.3% 13.4% 2.1% Worst CV health profile Best CV health profile 7? Laitinen et al. (2012). Circulation. 125: 1971-1978 The number of ideal CV health markers in youth predicts future arterial health ~ 12 years older in terms of vascular age Physical activity, and health: a life course perspective Low PA/ High PA/..and lower risk of future type II diabetes, hypertension, high LDL and high triglycerides Child health Adult health Laitinen et al. (2012). Circulation. 125: 1971-1978 At least five a week. Evidence on the impact of physical activity and its relationship to health. A report form the Chief Medical Officer. Department of Health. (2004). 2
Risk of clustered risk factors 21/11/2017 Physical activity How much daily physical activity should 5-18 year olds be performing? 1 hr MINIMUM! How many kids meet these guidelines? How many 5 18 year olds achieve this? 32% 24% Boys Girls moderate or vigorous At what intensity? How many kids meet these guidelines? How many 11 15 year olds achieve this? 7% <1% Boys Girls Are 60 minutes per day enough? 34 53 70 88 131 1732 boys and girls measured at 9 and 15 years Physical activity levels decline during adolescence Andersen et al. (2006). Lancet. 368: 299-304 Physical activity, and health: a life course perspective Low PA/ Children and adolescents are not doing enough physical activity High PA/ Over 6,000 children in 30 studies (each > 4 weeks) The average physical activity intervention increased daily physical activity by: At least five a week. Evidence on the impact of physical activity and its relationship to health. A report form the Chief Medical Officer. Department of Health. (2004). 4 mins 3
Key messages so far. Over 11,515 11 16 year olds The average physical activity intervention increased daily moderate/vigorous physical activity by: CVD starts in childhood and is related to risk factor status CVD risk factors in youth predict CVD burden in adulthood Physical activity lowers CVD risk Current guidelines are a minimum of 60 min per day Most children fail to achieve this Evidence suggests that 90 min per day should be the minimum and interventions only increase activity by a small amount 2 mins And now for some good news Short bouts of vigorous intensity physical activity improves health outcomes 605 youth aged 9-17 years (41% boys) Our programme of research Quality, not quantity? Vigorous Moderate Vigorous Moderate Vigorous Moderate Physical activity intensity, and CVD risk Observational studies Exercise intensity and CVD risk in youth Experimental studies Acute and chronic exercise interventions Traditional and novel risk factors for CVD Daily VPA needed for this benefit? < 8 mins Hay et al. (2012). Arch Pediatr Adoles Med. 166: 1022-1029 Dr Bert Bond Dr Emma Cockcroft Adam Malik Sascha Kranen Ricardo Oliveira Physical activity intensity, sedentary time, TV viewing and on CVD risk: HELENA study Physical activity Sedentary Fitness LPA MPA VPA ST TV viewing CRF (min/day) (min/day) (min/day) (min/day) (min/day) (ml/kg/min) MF 534 European adolescents (252 males) aged 14-16 years old Accelerometer derived PA and sedentary time TV viewing by questionnaire Cardiorespiratory by 20 m shuttle test Muscular by handgrip strength Aim: What are the associations of different PA intensities (MPA, VPA), total sedentary time, TV viewing, CRF and muscular on CVD risk factors? Which lifestyle factor is most important? Barker et al. (revise and resubmit) BMI 0.120 P=0.007 WC 0.139 P=0.001 SumSF 0.109 P=0.008 TG -0.055 P=0.22 HOMA IR -0.014 P=0.74 CVDR 0.064 P=0.16-0.019 P=0.67-0.032 P=0.47-0.030 P=0.46-0.022 P=0.62-0.027 P=0.52-0.050 P=0.27-0.110 P=0.018-0.089 P=0.055-0.159-0.141 P=0.003-0.062 P=0.17-0.159 P=0.001-0.043 P=0.31-0.009 P=0.83 0.009 P=0.82 0.030 P=0.49 0.009 P=0.83 0.019 P=0.67 0.080 P=0.064 0.058 P=0.17 0.048 P=0.23 0.102 P=0.018 0.173 0.141 P=0.001-0.408-0.330-0.444-0.114 P=0.06-0.096 P=0.10-0.388 Adjusted for age, sex, maturity and socioeconomic status. CVDR = clustered risk score based on SumSF, BP, blood lipids and HOMA-IR -0.537-0.507-0.592 0.039 P=0.53 0.015 P=0.80-0.340 Increasing levels of vigorous physical activity and, and reducing light physical activity and TV viewing time, are important for improving health outcomes. 4
Research Q: i) Can exercise protect against the fall in blood vessel function after a high fat meal? ii) Is intensity important? 10 boys, 10 girls (13-15 y) completed 3 laboratory visits Assessment of blood vessel health A high fat drink impairs blood vessel function Exercise dramatically influences blood vessel health 10.8% HIIE % increase in artery width 8.6% 7.4% MIIE Control CON HIIE MIE Before Exercise After Exercise 3 h after milkshake Bond et al. (2015). AJP Heart Circ. 308(11): 1443-50 Bond et al. (2015). AJP; 308: H1443-H1450 Research Q: What is the effect of 2 weeks of HIIT on traditional and novel CVD risk factors in adolescents? Sixteen 13-14 year olds (7 female) were recruited 3 withdrawals due to illness (male, female) and unrelated injury (male) Four visits to the laboratory over a 3 week period Traditional and novel CVD risk factors pre, 24 h post and 72 h post Visits 2-4 Fasted Postprandial Anthropometrics Aerobic Fasted and postprandial 8-10 1 min intervals @ 90% peak power with 75 s of recovery Fasted and postprandial Fasted, postprandial and aerobic Bond et al. (2015). Am J Physiol Heart Circ Physiol. 309: H1039-1047 = blood sample (glucose, insulin, TAG, TC, HDL) = blood vessel function Breakfast = high fat and high sugar meal Bond et al. (2015). Am J Physiol Heart Circ Physiol. 309: H1039-1047 Research Q: What is the effect of 2 weeks of HIIT on traditional and novel CVD risk factors in adolescents? Blood vessel function (% diameter change) ES = 0.70 ES = 1.01 ES = 0.60 = pre training = 1 day after training = 3 days after training There were no improvements in traditional CVD risk factors following training Bond et al. (2015). AJP Heart Circ. 309(6): 1039-47 HIIE better than MIE: Improving blood vessel health Lowering blood pressure Increasing fat oxidation Improving control of blood glucose Improving the regulation of the heart HIIE the same as MIE: Lowering fat in the blood HIIE may be a useful method to increase vigorous intensity physical activity and the health status of children and adolescents Exmouth Community College 5
Is HIIE or continuous moderate intensity exercise more enjoyable? N=54, 12-15 y olds (27 males) HIIE evokes elevated feelings of: Success Excitement Reward Concern: HIIE will not be adopted or maintained Malik et al. (2017). Eur J Sport Sci. 17: 1335-1342 Does HIIE evoke unpleasant feelings? Malik et al. (revise and resubmit). Incremental test to exhaustion HIIE at 90% maximum does not promote unpleasant feelings # HIIE vs MIIE W2 to endw, ES= 0.34 to 0.75 W1 to W8, ES= 0.49 to 1.49 HIIE MIIE Does HIIE evoke unpleasant feelings? The intensity of HIIE may range from ~ 70% maximum to allout sprints Question: Does the intensity of the HIIE matter? 70% vs. 85% vs. 100% HIIE > 90% seems to evoke unpleasant feelings 100% Malik et al. (in preperation). Quick recap Research programme: Quality, not quantity Vigorous intensity physical activity drives improvements in cardiovascular health (< 10 minutes per day) HIIE, a form of vigorous intensity physical activity, improves a range of health outcomes in youth HIIE is perceived to be more enjoyable than moderate intensity exercise and is not aversive if the intensity is 90% maximum HIIE could serve as a useful model to improve the health status in youth Data presented are efficacy studies. What about the effectiveness of HIIE in the school setting? Paper will be available in the coming days 6
HIIE in the school setting (n=15 studies) Study design Participants Median sample size = 55 37% females Age range: 9-17 y Recruitment data (range: 19-97%, n=4) Setting Primary (n=5) Secondary (n=9) Special education (n=1) Comparative group PE lessons Continuous aerobic exercise or HIIE Outcomes cardiorespiratory (11/15) waist circumference (4/6) blood pressure (4/7) % body fat (3/10) BMI (2/9) triglycerides (1/5) glucose (4/5) Diabetes, smoking, high cholesterol, obesity, hypertension, low Bond et al. (in press). Open Access Journal of Sports Medicine. Blair et al. 2009 BJSM Which is more powerful for health: physical activity vs.? Interventions to improve are important as levels are declining Data generated from 27 countries in children aged 6-19 year olds between 1958 to 2003. *Fatness explains ~ 40% of the fall in aerobic Being unfit warrants consideration as a risk factor, distinctly from inactivity, and worthy of screening and intervention Williams (2001). Med Sci Sport Exerc. 33: 754-761 Tomkinson and Olds (2007). Med Sport Sci. 50: 46-66 HIIE in the school setting (n=15 studies) Prescription of HIIE in the school setting Study design Participants Median sample size = 55 37% females Age range: 9-17 y Recruitment data (range: 19-97%, n=4) Setting Primary (n=5) Secondary (n=9) Special education (n=1) Comparative group PE lessons Continuous aerobic exercise or dose of HIIE Outcomes cardiorespiratory (11/15) waist circumference (4/6) % body fat (3/10) BMI (2/9) blood pressure (4/7) triglycerides (1/5) glucose (4/5) Delivery: Incorporate into PE Lunch breaks After school Modality: Running Cycling Cross-trainer Boxing Dance Drills (e.g. basketball) Skipping High intensity interval exercise Work interval duration: 10 to 60 s Work:rest duration: > 1.0 Duration: 2-15 weeks (average = 7 weeks) Frequency: 2-3 times per week Intensity: ~ 90 % heart rate max Hard/very hard on exertion scale Number of work intervals: 4 to 40 Bond et al. (in press). Open Access Journal of Sports Medicine. Bond et al. (in press). Open Access Journal of Sports Medicine. 7
Example: Haytor View Primary School, Newton Abbott School initiative to increase understanding of physical activity and its impact on health Staff, parents and pupils Incorporated vigorous activity into PE lessons and during the school day (e.g. breaks) School booklet Guide activities (skipping, running, jumping etc) What about academic performance? Regulation of cerebral blood flow Take home messages #1 CVD is the biggest killer and starts in childhood Physical activity can reduce CVD risk in youth But our kids are not active enough Public health guidelines call for 60 min per day minimum This should be closer to 90 min per day Attempts to increase physical activity in schools typically fail Take home messages #2 Performing ~ 8-10 minutes of daily vigorous intensity activity is cardio protective High-intensity exercise is a method to increase vigorous intensity activity and improves a range of health outcomes, including High-intensity exercise appears enjoyable and is not associated with unpleasant feelings if performed below ~ 90% maximum Studies suggest high-intensity exercise may have merit in the school setting and represents an area for future research Thanks to the @CHERC_UoE team Thanks to our funders and participants Blundell s School (Tiverton) Exmouth Community College (Exmouth) Sidmouth College (Sidmouth) St Luke s School (Exeter) West Exe School (Exeter) Government of Malaysia Northcott Devon Medical Foundation 8
CHERC Basic and applied paediatric exercise and health science Established 1986 Currently have 6 staff, 10 PhD students and 3 research fellows Queen s Anniversary Prize CHERC Bone research PRO-BONE study (EU funded) Effect of sports participation on bone mass and geometry in young athletes Swimmers, cyclists and soccer players 3 year longitudinal study including 9 month intervention using plyometric jumps CHERC Young athlete Young athlete s heart (Heart Research UK) Cross-sectional study looking at size and function Soccer players vs normal children Children with septal defects Techniques (ultrasound) Training effects on cardiac size and function Health and wellbeing of adolescent runners (ESRC) England Athletics Overtraining incidence, symptoms and causes Longitudinal data with addition of injury, training load, drop out CHERC Exercise medicine Exercise and adolescents with cystic fibrosis (CF Trust SRC) Measurement of physical activity, facilitators and barriers Interaction of CF and medication on exercise tolerance Design of clinical tool to assess On-line platform to increase physical activity 9